Impact evaluation of a healthy lifestyle intervention to reduce cardiovascular disease risk in health centers in San José, Costa Rica and Chiapas, Mexico

The title of the study was “Primary health and community-based support model to lower the risk of cardiovascular diseases in individuals with type 2 diabetes mellitus and/or arterial hypertension in urban areas of San José, Costa Rica and Tuxtla Gutierrez, Chiapas”.

Starting in 2011, researchers based at the Schools of Nutrition of the University of Costa Rica and the University of Sciences and Arts of Chiapas conducted a formative research phase including focus group discussions and key informant interviews to gain an understanding of patient knowledge and perceptions of chronic disease and the health care service delivery context in each of the two settings [13]. Jointly, the research teams in both settings defined the content for the educational sessions, drawing on the CVD risk reduction education materials from the previous study conducted in Guatemala; content that was considered to be most relevant and important, based on focus group discussions with patients and interviews with health care providers, was organized into six lessons. The method for teaching was also defined jointly and described in a manual for facilitators. Then, each research team adapted the training materials to the local context, based on what was learned during the focus group discussions. During the adaptation process, appropriate terms and names that are typically used in each setting were changed in the education materials. The materials were then validated to ensure that they would be understood. The result of this process were two sets of manuals and teaching materials, with the same content and lesson plans, but with adaptations appropriate for each setting. A project name and logo was developed in each site: Corazón Pura Vida in San José, Costa Rica and Corazón and Sano y Fuerte in Chiapas, Mexico.

Following the adaptation and validation process, the research team conducted training sessions with health care staff based at the intervention government primary care health centers in each of the two settings. In each setting, two health centers were selected for the intervention. Health promoters (in both countries, paid employees within the formal health care system) and other health center personnel that work with patients with chronic conditions (nurses, nutritionists, and physicians) participated in training sessions with the study team -- faculty from the School of Nutrition in each setting. Training sessions for health center staff were conducted in the primary care health centers and were each 2 hours long.

The training sessions focused on the use of the adapted manual and educational materials and key aspects of conducting group education sessions; the aim was to prepare health care staff both to share content to increase patient knowledge and also to promote patient-level behavior change. Training for the health care workers began with two sessions focused on the facilitation of participatory, situated group education sessions and the format to be followed as outlined in the manual. Situated learning takes into account and is situated in people’s context, their cultural understanding of health and disease, their concerns, vocabulary, resources, and their daily experience [14]. Then prior to each of the six group education sessions with patients, a training session for health care staff was offered on the specific content of that session, where the research team modeled the educational session, followed by active discussion. Halfway through the intervention, the research team offered a feedback session, to give the health care staff an opportunity to reflect and reorient their work so that they could better manage the group sessions according to situated education. The extent to which the healthcare workers adhered to the protocol was noted by an observer from the research team and quality criteria were used to assess each of the sessions; an explanation of these criteria and the process that was used will be reported in a forthcoming publication.

Health promoters, supported by other health care personnel from their primary care team, were responsible for organizing and conducting the 2-hour group education sessions with patients about CVD, risk factors, and healthy heart behavior. The sessions were designed to be interactive and were no larger than 20 patients. Patients were able to participate during any of the educational sessions once they were enrolled in the study, and did not have to follow the same sequence of educational sessions, in order to incorporate new patients. All participants had the opportunity and were encouraged to participate in six educational sessions led by health promoters and other members of the primary care team, and during which one or more members of the research team was also present. Each one of the six sessions was offered multiple times in order to allow participants to have the opportunity to take part if they missed one of the sessions. The summary box (Table 1) presents the six sessions, content, and the aim of the session and expected changes in participants.

At baseline, all participants were classified as having low, medium, or high global cardiovascular disease (CVD) risk, using a World Health Organization risk prediction chart [15]. The WHO risk prediction chart uses easy-to-measure parameters: sex, age, blood pressure, presence or absence of diabetes, and tobacco use. The chart indicates total 10-year risk of a fatal or non-fatal cardiovascular event (myocardial infarction or stroke) and according to the 10-year risk of a CVD event, patients are stratified as follows: low risk is <10 %; medium risk is 10 % to < 20 %; and high risk is 20 % to < 30 % and very high risk (coupled with high risk in this case) is 30 %.

To reinforce what patients were learning in the health education sessions, home visits were made by the research team to patients with medium or high risk. In Costa Rica, high-risk patients did not receive a home visit because as a part of the usual care practice they were expected to show up for check-ups at the health center more frequently than medium and low risk patients. In both countries, all intervention participants were called on a monthly basis to remind them to participate in the educational sessions.

Figure 1 presents the conceptual model for the healthy lifestyle intervention to reduce the risk of cardiovascular disease implemented in government primary care health centers in San José, Costa Rica and Tuxtla Gutiérrez, Chiapas, Mexico. The intervention draws on three theoretical frameworks: the Health Belief Model [16], Social Learning theory [17] and the Trans-theoretical model [18]. The conceptual model for the intervention posits that participants exposed to the group education sessions would be more likely to have increased knowledge, improved self-efficacy, and be in a higher stage-of-change (in contrast to patients in the comparison group) and these changes in cognitive factors could lead to increased healthy behavior, and in turn, clinical outcomes might improve. The analytic framework and empirical analyses do not measure exactly all of the steps in the model; other techniques including path analyses would have been required. Individual patient characteristics (age, sex, years of formal schooling, distance to the health center, working, living alone, and diabetic and/or hypertensive disease status) may influence knowledge, self-efficacy, stage-of-change and behavior, and are therefore included in the model as potential confounders to be controlled for in the analysis [19].

The study used a prospective, longitudinal, nonequivalent pretest-posttest comparison group design, and was conducted in parallel in each of the two countries. The health education intervention for patients was implemented from November 2011 to December 2012. Participants were enrolled in the study during a 4-month period and were followed-up over a period of 8 months with data collected at baseline, mid-point, and 8 months. The 8-month follow up was determined as the shortest time frame that would allow patients to participate in the 6 different educational sessions. Data were also gathered for participants in a usual care group at the same time points as for the intervention group.

Costa Rica and Chiapas were chosen as the sites to implement the study because both sites use paid health promoters (primary health care workers) within the official systems, and have an already existing infrastructure and programs for patients with type 2 diabetes and arterial hypertension. Other countries in Mesoamerica have limited or variable infrastructure and programs for chronic disease care and prevention as their health care systems are primarily oriented toward maternal and child health and infectious disease. The intervention and comparison health centers in each setting were selected for inclusion in the study in coordination with health authorities, aiming to be similar with respect to the services offered (laboratory, pharmacy and clinical care), number of patients served, and socio-economic status of the population. In each country setting, intervention and comparison group health centers were in different parts of the city in order to avoid contamination. The health center staff provided the research study team with a list of patients identified as having diabetes, hypertension or both conditions; the research team was in charge of selecting eligible patients at both the intervention and comparison health centers who fit the study’s inclusion criteria. The process for selecting patient participants was done similarly in both countries.

In Costa Rica, participants were recruited at health centers of the Caja Costarricense de Seguridad Social, the Costa Rican Social Security Institute, that offers insurance coverage to the whole population. In Tuxtla Gutiérrez, Chiapas participants were recruited at health centers of the Secretary of Health, operating under Seguro Popular, or popular insurance, that covers about a quarter of the population in Tuxtla Gutiérrez. In addition in Mexico, a cash transfer program called Oportunidades has been operating for over a decade in which patients have several requirements, including attending health promotion sessions on different topics. Documented differences in the health care context and resources between the countries included: human resources, medications, and routine care provided to patients with chronic conditions.

The study protocol was reviewed and approved by the Institutional Review Boards of the RAND Corporation (study # 2010–0700), the Institute of Nutrition of Central America and Panamá, the University of Costa Rica, the Costa Rican Social Security Institute and the Health Institute of the State of Chiapas.

Sample size was calculated at 75 patients in each of the intervention and comparison groups in each country, and the study teams aimed to recruit up to 90 patients to account for drop-outs and loss to follow-up. The sample size was calculated based on the experience of the pilot study conducted in Guatemala in which 75 patients were recruited for a study with a similar time frame and patients experienced significant reduction in mean systolic blood pressure of 27.2 mmHg.

Individual participants were selected from patients registered at public health centers who had a diagnosis of hypertension and/or type 2 diabetes, certified by a physician. The selection of patients to participate in the study was consecutive. All potential participants were offered information about the research and those who were interested granted written consent to participate.

The inclusion criteria for participating in the study were: being 21 years or older, residing in the area served by the selected health center, literate, and diagnosed with hypertension and/or type 2 diabetes. Intervention group participants also had to be willing to comply with proposed educational activities, including attendance at training sessions with support staff based at the health center.

The exclusion criteria were: previously experienced complications from diabetes (chronic kidney disease, peripheral circulation of the retina, organ damage), a history of stroke (thrombosis, ischemia, aneurysm) or cardiac problems (angina, infarction). Other criteria for exclusion included the presence of disease or mental impairment preventing their understanding of the instructions provided as part of the educational strategy; physical defect, pregnancy, or disability preventing regular physical exercise. A screening questionnaire was used with patients to define who should be excluded from the study and patient records were then used to verify the information.

Patients in the usual care group received a clinic visit with their primary care physician and laboratory tests. In Costa Rica, the usual care for patients with diabetes is every 3 months and for hypertension is every 4 months and patients receive their medications the day of their clinic visit. For Chiapas, patients with diabetes and hypertension were seen every month and at the same monthly visit they have relevant lab tests done and pick up their medications.

The outcomes measured in this study are presented in Fig. 1. The cognitive and behavioral measures were knowledge, self-efficacy, stage-of-change, dietary behavior and physical activity. A knowledge questionnaire was designed by project staff based on the key concepts presented in the group education sessions and was used at baseline and 8-months focusing on the topics covered in the health education intervention (maximum of 45 points). A sample question from the knowledge questionnaire in the topic of diabetes was to mark off which of the following ways can let us know that foods are high in carbohydrates – food that: a) are very watery, b) are sweet tasting and do not say “without sugar”, c) are doughy, pasty or floury, and d) have a lot of fiber. A scale of self-efficacy (with questions relevant for patients with hypertension and/or diabetes) was created based on an instrument titled Self-Efficacy for Diabetes designed for diabetics at the Stanford Patient Education Reference Center [20], with a maximum of 15 points. A sample question from the self-efficacy scale was: how confident do you feel that you can control your condition so that it does not interfere with the things you want to do? A stages-of-change scale was designed using 8 questions focused on topics emphasized in the group education sessions (medication adherence and care, diet, physical activity, family communication, and stress management); the scale ranged from 0–32 points. A sample question on stages-of-change was to mark off the stage in which the patient finds his or herself for: taking medications at the recommended time and in the recommended amount. A diet behavior index was created using a food consumption and dietary behavior questionnaire designed by the project team, with a maximum of 14 points. A sample question from the diet questionnaire was: do you add salt to your food after it has been prepared (never, always, sometimes?). Physical activity was captured using the International Physical Activity Questionnaire (IPAQ) Short Form (www.​ipaq.​ki.​se) and was summarized as meeting the recommended minutes of aerobic activity per week: at least 150 min of moderate-level activity or 75 min of vigorous-level activity [21]. Instruments developed by staff for the intervention were validated for understandability with 5–10 patients in each country setting; the patients attended the selected health centers but were not study participants.

The clinical outcomes were: body mass index, systolic blood pressure (mmHg), diastolic blood pressure (mmHg), and fasting blood glucose. All clinical outcomes were captured while fasting. Body mass index was calculated as (kg/m²). Resting blood pressure was measured after a 10 min rest in the seated position with a calibrated digital monitor (CITIZEN, Model CH 432) and each country team used its own monitor for the study; the average of three measurements taken 2 min apart, within 6 mmHg, was used. Plasma glucose was measured in the primary health care laboratories using conventional methods in Costa Rica, while in Mexico, the finger-prick method was used.

Individual patient characteristics that were included as co-variates in the regression analyses were: age (in years), sex, formal education level (years studied), works currently or is not currently employed, lives alone or not, distance from the health center (categorized as being less than 1 km, 1–2, 2–4 or greater than 4 km to the primary care health center), if diabetic or not, and if hypertensive or not.

The database was constructed using REDCap, [22] and data were double-entered on-site in Costa Rica and in Chiapas. Data were compared for inconsistencies and corrected and then were transferred to Stata SE version 12 (StataCorp LP, College Station, TX, USA) for statistical analysis.

The analysis was conducted separately for the two sites given the substantial difference in contexts and patient populations. Descriptive statistics were used to compare intervention and comparison group participants at baseline; an unpaired t-test with equal variances was used to measure differences between the two groups for continuous variables, and a X² analysis was used for categorical variables.

For the impact evaluation, the generalized estimating equation (GEE) method, with robust standard errors, was used comparing baseline to end-point, adjusting for baseline. The treatment and comparison groups were coded with a (1/0) variable, and an interaction with time was generated. An intention-to-treat analysis was conducted. For the regression analyses, a priori models were defined and all covariates included simultaneously. Linear regression models were used for: body mass index, systolic blood pressure, diastolic blood pressure, blood glucose, knowledge, self-efficacy, stage-of-change, and diet index. A logistic regression model was used for whether recommended physical activity guidelines were met or not. For the intervention group only, a multivariate regression analysis was conducted to test for a dose–response relationship of exposure to educational sessions and health outcomes, comparing changes for outcomes at 8-month follow-up to baseline; for the dose–response analysis, linear regression models were used for all outcomes.